AFI, FFI and CFI are alternate, fixed and conventional furrow irrigation, respectively. Values are means of three plots for each treatment.

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Table 2.Root and trunk water flows of pear trees in an orchard under three irrigation methods

Treatments

DAB

Root sap flow (l)

Trunk sap flowa

Total (l)

Average (l d–1)

Total (l)

Average (l d–1)

(mm d–1)

West

East

West

East

WRI

0–26

160.68 a

151.32 a

6.18 a

5.82 a

1704.82

65.57

3.65

27–35

59.40 a

56.97 a

6.60 a

6.33 a

607.32

67.48

3.76

36–66

211.11 a

218.55 a

6.81 a

7.05 a

2880.83

92.93

5.17

67–89

164.34 a

159.27 a

7.14 a

6.93 a

2314.93

100.65

5.6

0–89

595.53 a

586.11 a

6.69 a

6.59 a

7507.90

84.36

4.69

27–89

434.85

434.79

6.9

6.90

5803.08

92.11

5.12

FPRI

0–26

154.92 a

151.38 a

5.97 a

5.82 a

1581.06

60.81

3.39

27–35

67.23 a

34.29 b

7.47 a

3.81 b

485.73*

53.97*

3.01*

36–66

269.70 a

129.27 b

8.70 a

4.17 b

2319.11*

74.81*

4.17*

67–89

190.50 a

113.16 b

8.28 a

4.92 b

1952.84*

84.91*

4.73*

0–89

682.35 a

428.10 b

7.67 a

4.81 b

6338.74*

71.22*

3.96*

27–89

527.43 a

276.72 b

8.37 a

4.39 b

4757.68*

75.72*

4.20*

APRI

0–26

152.58 a

154.68 a

6.33 a

6.18 a

1598.48

61.48

3.42

27–35

33.48 b

63.72 a

3.72 b

7.08 a

477.66*

53.07*

2.96*

36–66

226.77 a

136.59 b

7.32 a

4.41 b

2480.62*

80.02*

4.46*

67–89

126.96 b

200.79 a

5.52 b

8.73 a

2263.64*

98.41*

5.48*

0–89

539.49 a

555.78 a

6.06 a

6.24 a

6820.40*

76.63*

4.26*

27–89

387.21 a

401.10 a

6.15 a

6.37 a

5221.92*

82.89*

4.61*

APRI, alternative partial root-zone irrigation; FPRI, fixed partial root-zone irrigation; WRI, the whole root-zone irrigation. Data are means of four measurements under the same treatment. Letters following numbers of consumptive water use indicate statistical significance of difference when the west and east sides within the same treatment were compared at P0.05 level (same letters indicate a non-significant difference). DAB means days after beginning of the experiment (Kang et al., 2002a)

a* Statistical significance at P0.05 level when compared with the corresponding values of WRI at the same experimental period. Statistical significance at P0.05 level of trunk sap flow in APRI compared with the corresponding values of FPRI in the same experimental period.